# Documentation Source Text

Check-in [8d9fe20890]

Overview
Comment: Fix a recently introduced error regarding collation sequences and compounds SELECT statements. family | ancestors | descendants | both | files | file ages | folders 8d9fe20890d6948892550c513f1c2be3bbb09da0 dan 2010-09-14 18:57:40
Context
 2010-09-14 19:10 Adding additional comparison operators to the list in datatype3.html. check-in: a43ee1e871 user: drh tags: trunk 18:57 Fix a recently introduced error regarding collation sequences and compounds SELECT statements. check-in: 8d9fe20890 user: dan tags: trunk 13:25 Add <> to the list of comparison operators in datatype3.html. check-in: 838bd2b455 user: drh tags: trunk
Changes

Changes to pages/lang.in.

 ```2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 ``` ```right SELECTs. ^The EXCEPT operator returns the subset of rows returned by the left SELECT that are not also returned by the right-hand SELECT. ^Duplicate rows are removed from the results of INTERSECT and EXCEPT operators before the result set is returned.

^For the purposes of determining duplicate rows for the results of compound SELECT operators, NULL values are considered equal to other NULL values and distinct from all non-NULL values. ^The collation sequences to compare text values values are determined as if the columns of the left and right-hand SELECT statements were the left and right-hand operands of the equals (=) operator. ^No affinity transformations are applied to any values when comparing rows as part of a compound SELECT.

^(When three or more simple SELECTs are connected into a compound SELECT, they group from left to right. In other words, if "A", "B" and "C" are all simple SELECT statements, (A op B op C) is processed as ((A op B) op C).)^

``` ``` | | > > | | ``` ```2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 ``` ```right SELECTs. ^The EXCEPT operator returns the subset of rows returned by the left SELECT that are not also returned by the right-hand SELECT. ^Duplicate rows are removed from the results of INTERSECT and EXCEPT operators before the result set is returned.

^For the purposes of determining duplicate rows for the results of compound SELECT operators, NULL values are considered equal to other NULL values and distinct from all non-NULL values. ^The collation sequence used to compare two text values is determined as if the columns of the left and right-hand SELECT statements were the left and right-hand operands of the equals (=) operator, except that greater precedence is not assigned to a collation sequence specified with the postfix COLLATE operator. ^No affinity transformations are applied to any values when comparing rows as part of a compound SELECT.

^(When three or more simple SELECTs are connected into a compound SELECT, they group from left to right. In other words, if "A", "B" and "C" are all simple SELECT statements, (A op B op C) is processed as ((A op B) op C).)^

```